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US 4,089,374 AGranted
Producing methane from coal in situ
AssigneeIn Situ Technology, Inc.
InventorRuel C. Terry
Life of this patent
Estimating the term…
Abstract
A well is drilled from the surface of the earth into an underground coal formation. The coal seam is fractured by fluids injected under pressure. Methane entrained in the cracks and fissures is removed to surface facilities. Coal seam in the vicinity of well bore is partially dewatered. Diameter of well bore in the coal section is enlarged first by underreaming the hole, then by a vertical in situ burn to form a collection chimney. Methane desorbed from the coal is withdrawn to surface facilities.
Claims12
A method of withdrawing methane from an underground coal deposit comprising the steps of
- establishing a first communication passage between the surface of the earth and an underground coal deposit,
- setting a casing in the said first communication passage,
- establishing a hermetic seal between the surface of the earth and the underground coal deposit,
- establishing three conduit means within the said first communication passage, the first of the said three conduit means being the annulus between the said casing and a tubing installed within the said casing, the second of the said three conduit means being the annulus between the said tubing and a pipe installed within the said tubing, and the third of the said three conduit means being the conduit within the said pipe,
- establishing a fracture radially outward from the said communication passage and into the said underground coal deposit,
- deepening the said first communication passage through the lowermost portion of the said underground coal deposit and into the underburden to form a sump,
- installing pump means in fluid communication with the said pipe,
- positioning the said pump means within the said sump,
- removing accumulated liquids from the said first communication passage through the said third conduit means and delivering the said liquids to the surface of the earth, and
- withdrawing methane from the said underground coal deposit through the said first conduit means.
7 more elements
Dependencies are inferred from the claim text.